JP2532566C - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Industrial Field of the Invention The present invention relates to a thermal transfer recording sheet which gives a matte print without gloss. B. Prior Art In recent years, thermal transfer recording for forming a transfer image on plain paper using a thermal printer, thermal facsimile, or the like has been actively developed. This thermal transfer recording is easy to maintain because the mechanism of the apparatus is simple, and the cost and maintenance cost are low. Also, clear and robust recording can be performed with low energy, and the use of multicolor ink sheets makes it relatively easy. Recently, it has been widely used because color recording can be easily performed. In particular, the use of monochrome type thermal transfer recording sheets is increasing due to the spread of thermal printers for thermal processing and thermal facsimile. However, a printed image recorded by a thermal printer is generally high in glossiness. In the case of multi-color recording, beautifulness is required in addition to the precision of recording as in fields such as graphic design and full color copying, but the glossiness of the image greatly contributes to these characteristics. On the other hand, in the monocle type recording, there are many fields such as character recording and copying. In this case, as for the readability of the printed image, the higher the glossiness, the greater the feeling of fatigue to human eyes, and this is one of the improvements in thermal transfer recording. That is, there is a strong demand for matte printing without gloss in monochrome thermal transfer recording. In such a situation, there are many known techniques for thermal transfer recording that provides matte print without gloss. For example, as in JP-A-60-11084, the surface of the base film on which the hot-melt ink layer is provided is matted by sand blasting, or is matted by kneading fine particles to form a film. A method is disclosed. Also, as disclosed in Japanese Patent Application Laid-Open No. 56-14891, a method is disclosed in which a matting agent is mixed and used in a heat-meltable thermosensitive ink. Further, Japanese Patent Application Laid-Open No. Sho 60-11083 discloses a method of providing a mat layer on a base film. C. Problems to be Solved by the Invention There are various problems in the patent gazettes cited in the above prior art. For example, the method of sandblasting the surface of the base film has disadvantages in that the strength of the film itself is reduced and the cost is high. The method of kneading the fine particles to form a film has a disadvantage that the degree of matting does not increase unless many fine particles are kneaded. In addition, in the method of mixing a matting agent into ink, the matting agent is generally a white inorganic pigment, and a small amount of matting agent is hardly effective in matting. Disadvantageously occurs. Furthermore, in the method of providing a mat layer on a base film, the mat layer ink is a material composed of a binder and an inorganic pigment, and it is necessary to increase the mat depth of the mat layer in order to make the matting effect appear. There is a disadvantage that the particle size of the inorganic pigment must be increased or the amount used must be increased. D. Means for Solving the Problems The present invention is to provide a thermal transfer recording sheet which solves the conventional drawbacks and gives a matte print without gloss. That is, the thermal transfer recording sheet provided by the present invention is a thermal transfer recording sheet in which an undercoat layer made of an olefin-based resin is provided on one surface of a base material, and a heat-fusible ink layer is further applied on the undercoat layer. In the sheet, the difference between the melting points of the undercoat layer and the heat-fusible ink layer is 20 ° C. or less, and the layers are mixed and melted near the interface between the undercoat layer and the heat-fusible ink layer after application. It is characterized by. Further, the olefin resin is at least one selected from the group consisting of polyethylene, polypropylene and polybutene, and the undercoat layer has a thickness of 0.5 to 5 μm on one surface of the substrate, preferably 1.0 to 3.0 μm. It is characterized by being coated with a thickness. Hereinafter, the present invention will be described specifically. The thermal transfer recording sheet of the present invention has a two-layer structure in which an undercoat layer is provided on one surface of a substrate, and a heat-fusible ink layer is provided on the undercoat layer. When the heat-fusible ink layer side of the base material and the image receiving paper are overlapped and heated and printed from the opposite surface of the base material using a thermal head, a printed image can be obtained by transfer onto the image receiving paper surface. In this case, the melting point between the undercoat layer and the heat-fusible ink layer has a difference of 20 ° C or less, so that the vicinity of the interface of each layer after coating is in a mixed state with each other, resulting in a clear layer structure. However, during printing, peeling occurs from the vicinity of the interface on either side of the undercoat layer or the hot-melt ink layer. More specifically, the adhesive force between the undercoat layer and the substrate is sufficiently large, and the adhesive force between the heat-fusible ink and the paper surface when heat is applied, and furthermore, the respective layers of the undercoat layer and the heat-fusible ink. By controlling the internal cohesion of the ink, the hot-melt ink peels (cohesive failure) from the vicinity of the interface on either side of the undercoat layer or the hot-melt ink layer during printing, and prints in matte tone on the image receiving paper The image is transferred. In the thermal transfer recording sheet of the present invention, as described above, the heat-fusible ink is peeled off from the vicinity of the interface on either side of the undercoat layer and the heat-fusible ink layer during the heat transfer and is transferred onto the image receiving paper. Therefore, the heat-applied portion of the thermal transfer recording sheet, that is, the portion where peeling has occurred, becomes a so-called roughened state with irregular irregularities, and has the effect of obtaining a printed image transferred in a matte tone with low glossiness. It is. That is, an object of the present invention is to peel off (cohesive failure) near the interface on either side of the undercoat layer and the hot-melt ink layer. As a result, a good matte transfer image can be obtained. The thermal transfer recording sheet of the present invention is superimposed on the image receiving paper and printed by heating with a thermal head to form a transfer print image on the image receiving paper. At the same time, the heat-fusible ink melts and permeates or adheres to the surface of the image receiving paper. After the heating printing, the thermal transfer recording sheet is peeled off from the superimposed image receiving paper. At this time, the peeling occurs near the interface on either side of the undercoat layer and the heat-fusible ink layer, and as a result, the thermal transfer recording sheet Heat application part, peeling (
It is considered that the portion where cohesive failure has occurred is in a so-called roughened state having irregular irregularities, and the imprint surface is matted. For these reasons, the thermal transfer recording sheet of the present invention is capable of obtaining a so-called matt print image with low glossiness. Next, the materials to be used will be described more specifically. As the base material, thin paper such as condenser paper, typewriter paper, tracing paper, synthetic paper, cellophane paper, and synthetic resin film such as polyester film, polyimide film, polyethylene film, polycarbonate film, Teflon film, etc. It is used after heat-resistant treatment so that it does not stick to the head. Of these examples, a polyester film is particularly preferred for the purpose of the present invention. The ink used in the hot-melt ink layer of the present invention is composed of a hot-melt substance, a colorant, a binder, a softener, and the like. Representative examples of the heat-fusible substance are shown below, but are not limited thereto. Examples of waxes include plant waxes such as rice wax, wood wax, candelilla wax, carnauba wax, animal waxes such as lanolin, dense wax, whale wax, shellac wax, montan wax, ozokerite, ceresin, etc. Petroleum waxes such as mineral wax, paraffin wax and microcrystalline wax, synthetic hydrocarbon waxes such as oxidized paraffin wax and low molecular weight polyethylene, ricinoleic amide, lauric amide, erucic acid amide, palmitic acid amide, oleic acid amide And amide waxes such as stearic acid amide and ethylene bisstearic acid amide. Examples of the metal soap include metal salts of higher fatty acids such as sodium stearate, sodium palmitate, potassium laurate, potassium myristate, calcium stearate, zinc stearate, aluminum stearate, and magnesium stearate. Examples of resins include polyamide resins, polyester resins, epoxy resins, polyurethane resins, polyacrylic resins, polyvinyl resins, polyvinyl chloride resins, cellulose resins, polyvinyl alcohol resins, petroleum resins, and terpene resins. Resins, polystyrene resins, polyolefin resins, elastomers and the like can be mentioned. Colorants include dyes and pigments such as oil-soluble dyes, disperse dyes, and colored pigments, but they can be used as needed. Hereinafter, specific examples will be given, but the present invention is not limited thereto, and two or more kinds may be used in combination. Examples of the oil-soluble dye include an azo dye, an azo metal complex dye, an anthraquinone dye, and a phthalocyanine dye. More specifically, examples of azo dyes include Solvent Ero-2 (CI11020, hereinafter the CI number is shown in parentheses) Solvent Orange 1 (11920), Solvent Red 24 (26105), Solvent Brown 3 (11360), and the like. As azo metal complex dyes, Solvent Yellow 19
(13900A), Solvent Orange 5 (18745A), Solvent Red 8 (12715)
, Solvent Brown 37, Solvent Black 123 (12195), etc., and as anthraquinone dyes, Solvent Violet 13 (60725), Solvent Blue 11
(61525), Solvent Green 3 (61565) and the like, and phthalocyanine dyes such as Solvent Blue 25 (74350). Examples of the disperse dye include an aminoazo or aminoanthraquinone dye and a nitroarylamine dye. More specifically, examples of aminoazo dyes include Disperse Yellow 3 (CI11855, hereinafter the CI number is shown in parentheses), Disperse Orange 3 (11005), Disperse Red 1 (11110), Disperse Violet 24 (11200). , Disperse Blue 44 and others. Examples of the aminoanthraquinone dye include Disperse Orange 11 (60700), Disperse Red 4 (60755), Disperse Violet 1 (61100), Disperse Blue 3 (61505), and the like. Nitroarylamine dyes include Disperse Yellow 1 (10345) and 42
(10338). Colored pigments include azo pigments (monoazo, bisazo, condensed azo pigments), dye lake pigments (acid dye lakes, basic dye lakes, mordant dye lake pigments), nitro pigments, nitroso pigments, phthalocyanine pigments, and high-grade pigments (vat dyes). Dye-based pigments, metal complex pigments, perylene pigments, isoindolinone pigments, quinacridone pigments, and the like. More specifically, Hanzo Yellow G is used as an azo pigment.
(CI11680, hereinafter the parentheses indicate CI No.), Hansa Yellow R (12710), Pyrazolone Red B (21120), Permanent Red R (12085), Lake Red C
(15585), Brilliant Carmine 6B (15850), Permanent Carmine FB (1249
0) (hereinafter referred to as monoazo pigment), benzidine yellow G (21090), benzidine yellow GR
(21100), permanent yellow NCR (20040) (above bisazo pigment), chromophtal yellow, chromophtal red (above condensed azo pigment) and the like. As dye lake pigments, quinoline yellow lake (47005), eosin lake (45380),
Alkaline Blue Lake (42750A, 42770A) (acid dye lake pigment), Rhodamine Lake B (45170), Methyl Violet Lake (42535), Victoria Blue Lake (44045), Malachite Green Lake (42000) (basic dye lake pigment) ), Alizarin Lake (58000) (mordanting dye lake pigment). As nitro pigments, naphthol yellow S (10316), as nitroso pigments, Pigment Green B (10006), naphthol green B (10020), and as phthalocyanine pigments, metal-free phthalocyanine blue (74100), phthalocyanine blue (74160), phthalocyanine green ( 74260). High-grade pigments include Anthrapyrimidine Yellow (68420) and Indanthrene Brilliant Orange GK (59305)
), Indaslen Blue RS (69800), Thioindigo Red B (73300) (Vatable dye-based pigment), Nickel Azo Yellow (12775) metal complex salt pigment), Perylene Red (71140), Perylene Scarlet (71137) (More Perylene pigment), isoindolinone yellow (isoindolinone pigment), quinacridone red Y (46500),
There is quinacridone magenta (73915). As a black pigment, there is carbon black (CI77265). As the binder, any of a water-soluble binder and a water-insoluble binder can be used. Specific examples of such a binder will be described below, but the present invention is not limited thereto, and two or more binders may be used in combination. As the binder, for example, polyvinyl alcohol, methyl cellulose, gelatin, hydroxyethyl cellulose, carboxymethyl cellulose, gum arabic, starch and derivatives thereof, casein, polyvinyl pyrrolidone, butyral resin, ethylene ethyl acrylate, styrene-butadiene copolymer, vinyl acetate resin, Examples thereof include a vinyl acetate copolymer, an acrylic resin, a methyl methacryl resin, a styrene / acrylonitrile resin, an ethylene-vinyl acetate copolymer, a polyester resin, and a petroleum resin. Examples of the softener include mineral oil, dibutyl phthalate, dioctyl phthalate, mineral spirit, and liquid paraffin. In addition to the above-mentioned heat-fusible substances, colorants, binders and softeners, additives such as surfactants, dispersants, antistatic agents, antioxidants, and ultraviolet absorbers may be added. Coating machines used for coating the undercoat layer and the heat-fusible ink layer on the substrate in the thermal transfer recording sheet of the present invention include hot melt coaters, air knife coaters, roll coaters, blade coaters, bar coaters, and the like. A known coater or a known printing machine using a flexographic method, a gravure method, or the like can be used. In addition, about solvent coating, it is possible with a general solvent, for example, methanol,
Ethanol, isopropyl alcohol, toluene, methyl ethyl ketone, acetone, ethyl acetate and the like can be appropriately used. The coating thickness of the undercoat layer is 0.5 to 5.0 μm, preferably 1.0 to 3.0 μm. The coating thickness of the hot-melt ink layer provided on the undercoat layer is 1 to 15 μm, preferably 2 to 10 μm, and more preferably 3 to 6 μm. E. Function The thermal transfer recording sheet according to the present invention is characterized in that an undercoat layer made of an olefin-based resin and a heat-meltable ink layer are sequentially applied to one surface of a substrate. The thermal transfer recording sheet of the present invention having such features has an effect that a matte print image with low glossiness can be obtained on an image receiving paper. Hereinafter, the present invention will be described specifically with reference to examples. In addition, "part" in an Example shows a weight part. F. Examples Example 1. On a non-coated surface of a 5.2 μm-thick polyester film provided with a heat-resistant treatment layer, an undercoat layer made of an olefin-based resin was used using a roll coater so as to have a coating thickness of 1.5 μm. And applied. As the olefin resin, an emulsion of polyethylene having a melting point of 93 ° C. was used. Subsequently, a hot-melt ink layer was applied on the undercoat layer with a bar coater using an aqueous hot-melt ink (melting point: 78 ° C.) having the following composition so as to have a coating thickness of 4 μm. Obtained. Carbon black 13 parts Ethylene-vinyl acetate copolymer 5 parts Petroleum resin 10 parts Polyethylene wax 72 parts The thermal transfer recording sheet obtained in this manner is used as an image receiving paper for thermal transfer recording (Mitsubishi Paper (
Co., Ltd., trade name: TTR-T), printed and printed at 1.3 mJ / dot using a thermal head printer manufactured by Matsushita Electronic Components Co., Ltd. Was obtained. The evaluation results are shown in Table 1. Example 2. Using a polypropylene emulsion having a melting point of 67 ° C. as a material for an undercoat layer, coating was performed with a roll coater to a coating thickness of 2 μm. Subsequently, the same heat-meltable ink as in Example 1 was applied to obtain a thermal transfer recording sheet, and printing was performed in the same manner as in Example 1. The evaluation results are shown in Table 1. Example 3. The same polyethylene used in Example 1 and a polyester resin having a melting point of 83 ° C were used.
A mixture of 2: 1 (melting point 90 ° C.) was applied with a hot melt coater to a coating thickness of 1.5 μm. Subsequently, the same heat-meltable ink as in Example 1 was applied to obtain a thermal transfer recording sheet, and printing was performed in the same manner as in Example 1. The evaluation results are shown in Table 1. Example 4 The same polyethylene and ethylene-vinyl acetate copolymer as used in Example 1 (melting point
A mixture (78 ° C.) of 3: 1 (melting point 89 ° C.) was applied with a hot melt coater so as to have a coating thickness of 1.5 μm. Subsequently, the same heat-meltable ink as in Example 1 was applied to obtain a thermal transfer recording sheet, and printing was performed in the same manner as in Example 1. The evaluation results are shown in Table 1. Comparative Example 1. As a material for an undercoat layer, an emulsion of polyethylene having a melting point of 130 ° C. and a coating thickness of 1.5 μm
m was applied using a roll coater. Subsequently, the same heat-meltable ink as in Example 1 was applied to obtain a thermal transfer recording sheet, and printing was performed in the same manner as in Example 1. The evaluation results are shown in Table 1. Comparative Example 2. An acrylic resin having a melting point of 65 ° C. was applied as an undercoat layer material using a hot melt coater so as to have a coating thickness of 1.5 μm. Subsequently, the same heat-meltable ink as in Example 1 was applied to obtain a thermal transfer recording sheet, and printing was performed in the same manner as in Example 1. The evaluation results are shown in Table 1. Comparative Example 3. A thermal transfer recording sheet was obtained by applying only the same heat-meltable ink as in Example 1 without the undercoat layer, and printing was performed in the same manner as in Example 1. Table 1 shows the evaluation results. Comparative Example 4. The emulsion of polyethylene having a melting point of 93 ° C. used in Example 1 was applied by a bar coater to a coating thickness of 6 μm. Subsequently, the same heat-meltable ink as in Example 1 was applied to obtain a thermal transfer recording sheet, and printing was performed in the same manner as in Example 1. The evaluation results are shown in Table 1. Comparative Example 5. The emulsion of polyethylene having a melting point of 93 ° C. used in Example 1 was applied by a gravure coater to a coating thickness of 0.2 μm. Subsequently, the same heat-meltable ink as in Example 1 was applied to obtain a thermal transfer recording sheet, and printing was performed in the same manner as in Example 1. The evaluation results are shown in Table 1. Evaluation method Glossiness evaluation method A 60-degree specular glossiness specified by JIS Z8741 was measured using a glossmeter (manufactured by Nippon Denshoku Industries Co., Ltd.
(Trade name: ND-1001DP). Printability Characteristic pattern and solid pattern on thermal transfer recording receiving paper (Mitsubishi Paper Corp., trade name: TTR-T) at a printing energy of 1.3 mJ / dot using a Matsushita Electronic Parts Co., Ltd. thermal head printer. It was printed and visually observed. Adhesive Strength to Substrate By peeling the thermal transfer recording sheet by hand 10 times, peeling of the undercoat layer and the heat-fusible ink layer from the substrate was observed. [Table 1] The thermal transfer recording sheet of Example 1 had a sharp and matte print image, although the adhesion to the substrate was slightly inferior. The thermal transfer recording sheet of Example 2 had excellent adhesion to the base material and provided a clear and matte printed image. The thermal transfer recording sheets of Examples 3 and 4 have excellent adhesion to the substrate by using a polyester resin and an ethylene-vinyl acetate copolymer in combination with the polyethylene used in the thermal transfer recording sheet of Example 1. A clear and matte printed image was obtained. The thermal transfer recording sheet of Comparative Example 1 is a case in which polyethylene having a melting point difference of 20 ° C. or more from the heat-fusible ink layer is used as the undercoat layer material. It did not reach a mixed state, was inferior in adhesion to the substrate and printability, and had a glossy printed image. The thermal transfer recording sheet of Comparative Example 2 was a case where an acrylic resin was used as a material for the undercoat layer. The thermal transfer recording sheet was inferior in adhesive strength to a substrate and printability, and had a glossy printed image. The thermal transfer recording sheet of Comparative Example 3 had only the hot-melt ink applied thereon.
The adhesive strength to the substrate was excellent, but the printability was slightly inferior, and the printed image was glossy. The thermal transfer recording sheet of Comparative Example 4 was formed by coating the polyethylene used as the undercoat layer material of the thermal transfer recording sheet of Example 1 with a thickness of 6 μm, and was inferior in adhesive strength to the substrate and printability, The printed image was also slightly glossy.
The thermal transfer recording sheet of Comparative Example 5 was formed by coating polyethylene having a thickness of 0.2 μm, which was used as the undercoat material of the thermal transfer recording sheet of Example 1, and the thermal shrinkage effect of the undercoat layer when heat was applied. It was insufficient, and the printed image was glossy. G. Effects of the Invention As described above, the thermal transfer recording sheet of the present invention has a lower glossiness of a printed image than the conventional thermal transfer recording sheet, is excellent in matte printability, and has extremely high industrial significance. is there.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 and 2 are views showing the structure of a thermal transfer recording sheet of the present invention. FIG. 1 is a configuration diagram in which a heat-resistant treatment layer is provided on the opposite surface of the base material, and FIG. 2 does not have a heat-resistant treatment layer. FIG. 3 and FIG. 4 are diagrams showing the configuration when the image is transferred onto an image receiving paper using a thermal head. FIG. 3 shows the matte print image of the present invention. FIG. 4 is a configuration diagram for providing a conventional glossy print image.

Claims (1)

Claims 1) In a thermal transfer recording sheet in which a subbing layer made of a hot-melt resin and a hot-melt ink layer are sequentially laminated on one surface of a substrate, the hot-melt resin is made of an olefin resin. , the difference between the melting point of the undercoat layer and the heat-fusible ink layer has a 20 ° C. or less, and Ri layer der were mixed molten each other in the vicinity of the interface undercoat layer and the heat-fusible ink layer after coating, and or
Thermal transfer recording sheet which undercoat layer is characterized that you have been Coating with a thickness of 0.5~5.0μm on one side of the substrate. 2) The thermal transfer recording sheet according to claim 1, wherein the olefin resin is at least one selected from the group consisting of polyethylene, polypropylene, and polybutene.
. 3) The thermal transfer recording sheet according to claim 1, wherein the substrate is a polyester film . 4) The thermal transfer recording sheet according to claim 1, wherein the glossiness of the printed surface is 30 or less in a measured value of a 60-degree specular glossiness specified in JIS Z8741 .